A 2005 model isn't all that old. I would try a Tracker dealer hoping Tracker still used the same window in newer models or still carried spares.
Another thing to try if the glass is flat and both sides are the same, is look at the drivers side and see if a manufacturer name/part number is etched in the glass for another option if Track doesn't carry the spare part.
most likely a taylor made window system. however looking at pictures, the glass is flat. so take out the other side, get a piece of glass cut, install and go boating.
